Thin film magnetic head and method of manufacturing the same

ABSTRACT

The present invention provides a method of manufacturing a thin film magnetic head, capable of easily manufacturing a thin film magnetic head with high precision, in which a magnetic shield layer is disposed so as to surround a magnetic pole layer from three directions of a medium outflow direction and two side directions. In a magnetic pole formation region surrounded by a first gap layer portion, a magnetic pole layer and a second gap layer portion are formed and the magnetic pole layer is covered with the first and second gap layer portions. After that, a write shield layer is formed on the first and second gap layer portions so as to surround the magnetic pole layer from three directions (a trailing direction and two side directions). Since a gap between the magnetic layer and the write shield layer exerting an influence on recording characteristics is specified on the basis of the thickness of the first gap layer portion, different from the case where the gap is specified on the basis of pattern precision of the photolithography technique, the gap is controlled with high precision.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thin film magnetic head having atleast an inductive magnetic transducer for recording and a method ofmanufacturing the same. More particularly, the invention relates to athin film magnetic head having a write shield layer for preventingspread of a magnetic flux emitted from a magnetic pole layer and amethod of manufacturing the same.

2. Description of the Related Art

In recent years, improvement in performance of a thin film magnetic headis demanded with improvement in areal density of a magnetic recordingmedium (hereinbelow, simply called “recording medium”) such as a harddisk. Examples of a known method of recording a thin film magnetic headare a longitudinal recording method in which the orientation of a signalmagnetic field is set to an in-plane direction (longitudinal direction)of a recording medium and a perpendicular recording method in which theorientation of a signal magnetic field is set to a direction orthogonalto the face of a recording medium. At present, the longitudinalrecording method is widely used. However, when a market trendaccompanying improvement in areal density is considered, it is assumedthat, in place of the longitudinal recording method, the perpendicularrecording method will be regarded as a promising method in future forthe following reason. The perpendicular recording method has advantagessuch that high linear recording density can be assured and a recordedrecording medium is not easily influenced by thermal fluctuations.

A thin film magnetic head of the perpendicular recording method has, forexample, a thin film coil for generating a magnetic flux, a magneticpole layer for emitting the magnetic flux generated by the thin filmcoil toward a recording medium, and a write shield layer (magneticshield layer) for preventing spread of a magnetic flux emitted from themagnetic pole layer. As a thin film magnetic head of this kind, a thinfilm magnetic head in which a write shield layer is disposed on atrailing side of the magnetic pole layer (medium outflow side) is known(for example, refer to Japanese Unexamined Patent Application Nos.05-325137 and 06-236526). Another example of the known methods is amethod of disposing a write shield layer so as to surround a magneticpole layer from three directions of a trailing direction and two sidedirections which are orthogonal to the trailing direction in order toeffectively prevent spread of a magnetic flux (refer to, for example,U.S. Pat. No. 4,656,546). The thin film magnetic heads have an advantageof improved recording density since a recording track width on arecording medium is narrowed on the basis of prevention of spread of amagnetic flux.

To spread a thin film magnetic head of the perpendicular recordingmethod, it is necessary to facilitate the manufacturing process as muchas possible in consideration of mass production. Although theconventional thin film magnetic head in which the write shield layer isdisposed so as to surround the magnetic pole layer from the threedirections of the trailing direction and the two side directions is veryexcellent from the viewpoint of prevention of spread of a magnetic flux,the head has problems such that the process of manufacturing the thinfilm magnetic head is difficult and the processing precision inmanufacture is insufficient. Consequently, at the time of manufacturingthe thin film magnetic head of this kind, it is desired to establish aneasy, high-precision manufacturing process.

SUMMARY OF THE INVENTION

The present invention has been achieved in consideration of suchproblems and its first object is to provide a method capable of easilymanufacturing a thin film magnetic head at high precision, in which amagnetic shield layer is disposed so as to surround a magnetic polelayer from three directions of a medium outflow direction and two sidedirections orthogonal to the medium outflow direction.

A second object of the invention is to provide a thin film magnetic headmanufactured by using the method of manufacturing a thin film magnetichead of the invention.

A method of manufacturing a thin film magnetic head according to a firstaspect of the invention, comprising a thin film coil for generating amagnetic flux and a magnetic pole layer having a magnetic pole tipportion for emitting the magnetic flux generated by the thin film coiltoward a recording medium traveling in a predetermined medium traveldirection, comprises: a first step of forming a first photoresist layerin a pattern so as to have a shape in plan view corresponding to a shapein plan view of the magnetic pole layer; a second step of forming afirst gap layer so as to cover the first photoresist layer and aperipheral region of the first photoresist layer; a third step offorming a second photoresist layer so as to cover the first gap layer; afourth step of exposing the first photoresist layer by etching at leastthe second photoresist layer and the first gap layer halfway; a fifthstep of removing the first and second photoresist layers to thereby forma magnetic pole formation region surrounded by the first gap layer in aregion from which the first photoresist layer is removed; a sixth stepof forming the magnetic pole layer in a pattern in the magnetic poleformation region so as to extend from a recording medium facing surfacewhich faces the recording medium in the direction away from therecording medium facing surface; a seventh step of forming a second gaplayer in a pattern on the magnetic pole layer to thereby surround themagnetic pole layer from three directions of a medium outflow directionin the medium travel direction and two side directions orthogonal to themedium outflow direction by the first and second gap layers; and aneighth step of forming a magnetic shield layer in a pattern on the firstand second gap layers so as to extend from the recording medium facingsurface in the direction away from the recording medium facing surfaceand to surround the magnetic pole tip portion of the magnetic pole layerfrom the three directions.

In the method of manufacturing a thin film magnetic head according tothe first aspect of the invention, in a magnetic pole formation regionsurrounded by a first gap layer, a magnetic pole layer and a second gaplayer are formed, and the magnetic pole layer is covered with the firstand second gap layers from three directions. After that, a magneticshield layer is formed on the first and second gap layer portions so asto surround the magnetic pole tip portion of the magnetic pole layerfrom three directions.

A method of manufacturing a thin film magnetic head according to asecond aspect of the invention, comprising a thin film coil forgenerating a magnetic flux and a magnetic pole layer having a magneticpole tip portion for emitting the magnetic flux generated by the thinfilm coil toward a recording medium traveling in a predetermined mediumtravel direction, comprises: a first step of forming a first photoresistlayer in a pattern so as to have a shape in plan view corresponding to ashape in plan view of the magnetic pole tip portion; a second step offorming a first gap layer so as to cover the first photoresist layer anda peripheral region of the first photoresist layer; a third step offorming a second photoresist layer so as to cover the first gap layer; afourth step of exposing the first photoresist layer by etching at leastthe second photoresist layer and the first gap layer halfway; a fifthstep of removing the first and second photoresist layers to thereby forma magnetic pole tip formation region surrounded by the first gap layerin a region from which the first photoresist layer is removed; a sixthstep of forming the magnetic pole tip portion in a pattern in themagnetic pole tip formation region so as to extend from a recordingmedium facing surface which faces the recording medium in the directionaway from the recording medium facing surface; a seventh step of forminga second gap layer in a pattern on the magnetic pole tip portion tothereby surround the magnetic pole tip portion from three directions ofa medium outflow direction in the medium travel direction and two sidedirections orthogonal to the medium outflow direction by the first andsecond gap layers; and an eighth step of forming a magnetic shield layerin a pattern on the first and second gap layers so as to extend from therecording medium facing surface in the direction away from the recordingmedium facing surface and to surround the magnetic pole tip portion fromthe three directions.

In the method of manufacturing a thin film magnetic head according tothe second aspect of the invention, in a magnetic pole tip formationregion surrounded by a first gap layer, a magnetic pole tip portion anda second gap layer are formed, and the magnetic pole tip portion issurrounded from three directions by the first and second gap layers.After that, a magnetic shield layer is formed on the first and secondgap layer portions so as to surround the magnetic pole tip portion fromthree directions.

A thin film magnetic head according to the first aspect of the inventioncomprises: a thin film coil for generating a magnetic flux; a magneticpole layer having a magnetic pole tip portion for emitting the magneticflux generated by the thin film coil toward a recording medium travelingin a predetermined medium travel direction, and extending from arecording medium facing surface which faces the recording medium in thedirection away from the recording medium facing surface; a first gaplayer disposed so as to be adjacent to the magnetic pole layer in twoside directions orthogonal to the medium outflow direction in the mediumtravel direction; a second gap layer disposed so as to be adjacent tothe magnetic pole layer in the medium outflow direction; and a magneticshield layer disposed so as to extend from the recording medium facingsurface in the direction away from the recording medium facing surfaceand so as to surround the magnetic pole tip portion of the magnetic polelayer from three directions of the medium outflow direction and the twoside directions via the first and second gap layers.

The thin film magnetic head according to the first aspect of theinvention has: the first gap layer adjacent to the magnetic pole layerin two side directions; the second gap layer disposed adjacent to themagnetic pole layer in the medium outflow direction; and the magneticshield layer surrounding the magnetic pole tip portion of the magneticpole layer from three directions of the medium outflow direction and thetwo side directions via the first and second gap layers. Thus, the thinfilm magnetic head can be manufactured by using the method ofmanufacturing a thin film magnetic head according to the first aspect ofthe invention.

A thin film magnetic head according to the second aspect of theinvention comprises: a thin film coil for generating a magnetic flux; amagnetic pole layer having a magnetic pole tip portion for emitting themagnetic flux generated by the thin film coil toward a recording mediumtraveling in a predetermined medium travel direction, and extending froma recording medium facing surface which faces the recording medium in adirection away from the recording medium facing surface; a first gaplayer disposed so as to be adjacent to the magnetic pole tip portion intwo side directions orthogonal to the medium outflow direction in themedium travel direction; a second gap layer disposed so as to beadjacent to the magnetic pole tip portion in the medium outflowdirection; and a magnetic shield layer disposed so as to extend from therecording medium facing surface in the direction away from the recordingmedium facing surface and so as to surround the magnetic pole tipportion from three directions of the medium outflow direction and thetwo side directions via the first and second gap layers.

The thin film magnetic head according to the second aspect of theinvention has: the first gap layer adjacent to the magnetic pole tipportion in two side directions; the second gap layer adjacent to themagnetic pole tip portion in the medium outflow direction; and themagnetic shield layer surrounding the magnetic pole tip portion fromthree directions of the medium outflow direction and the two sidedirections via the first and second gap layers. Thus, the thin filmmagnetic head can be manufactured by using the method of manufacturing athin film magnetic head according to the second aspect of the invention.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are cross sections showing a sectional configuration ofa thin film magnetic head according to an embodiment of the invention.

FIG. 2 is a plan view showing the configuration of main components ofthe thin film magnetic head illustrated in FIGS. 1A and 1B.

FIG. 3 is a perspective view showing the configuration of maincomponents of the thin film magnetic head illustrated in FIGS. 1A and1B.

FIGS. 4A and 4B are cross sections for explaining one of processes ofmanufacturing the thin film magnetic head shown in FIGS. 1A and 1B toFIG. 3.

FIGS. 5A and 5B are cross sections showing a process subsequent to FIGS.4A and 4B.

FIGS. 6A and 6B are cross sections showing a process subsequent to FIGS.5A and 5B.

FIGS. 7A and 7B are cross sections showing a process subsequent to FIGS.6A and 6B.

FIGS. 8A and 8B are cross sections showing a process subsequent to FIGS.7A and 7B.

FIGS. 9A and 9B are cross sections showing a process subsequent to FIGS.8A and 8B.

FIGS. 10A and 10B are cross sections showing a process subsequent toFIGS. 9A and 9B.

FIGS. 11A and 11B are cross sections showing a process subsequent toFIGS. 10A and 10B.

FIG. 12 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 5A and 5B.

FIG. 13 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 6A and 6B.

FIG. 14 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 7A and 7B.

FIG. 15 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 8A and 8B.

FIG. 16 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 9A and 9B.

FIG. 17 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 10A and 10B.

FIG. 18 is a plan view showing the configuration corresponding to thesectional configuration illustrated in FIGS. 11A and 11B.

FIG. 19 is a plan view showing the configuration for explaining anexample of formation of a seed layer.

FIG. 20 is a diagram showing dependency on an incident angle of etchingrate.

FIG. 21 is a cross section for explaining an advantage of a method ofmanufacturing a thin film magnetic head according to an embodiment ofthe invention.

FIG. 22 is a cross section for explaining problems of a method ofmanufacturing a thin film magnetic head as a comparative example of themethod of manufacturing a thin film magnetic head according to anembodiment of the invention.

FIG. 23 is a cross section showing a modification of the configurationof the thin film magnetic head illustrated in FIG. 21.

FIG. 24 is a cross section showing another modification of theconfiguration of the thin film magnetic head illustrated in FIG. 21.

FIGS. 25A and 25B are cross sections for explaining one of formingprocesses of a first modification of the method of forming a writeshield layer.

FIGS. 26A and 26B are cross sections showing a process subsequent toFIGS. 25A and 25B.

FIGS. 27A and 27B are cross sections showing a process subsequent toFIGS. 26A and 26B.

FIGS. 28A and 28B are cross sections for explaining one of formingprocesses of a second modification of the method of forming the writeshield layer.

FIGS. 29A and 29B are cross sections showing a process subsequent toFIGS. 28A and 28B.

FIGS. 30A and 30B are cross sections for explaining a process in amanufacturing process of a third modification of the method of formingthe write shield layer.

FIGS. 31A and 31B are cross sections showing a modification of theprocess of the thin film magnetic head illustrated in FIGS. 1A and 1B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention will now be described in detail hereinbelowwith reference to the drawings.

First, the configuration of a thin film magnetic head according to anembodiment of the invention will be described with reference to FIGS. 1Aand 1B to FIG. 3. FIGS. 1A and 1B show sectional configurations of athin film magnetic head. FIG. 1A shows a section parallel to an airbearing surface 20 and FIG. 1B shows a section perpendicular to the airbearing surface 20. FIG. 2 is a plan view showing the configuration ofmain components of the thin film magnetic head illustrated in FIGS. 1Aand 1B. FIG. 3 is a perspective view showing the configuration of themain components. An upward arrow B shown in FIGS. 1A and 1B indicatesthe travel direction of a recording medium (not shown) relative to thethin film magnetic head (medium travel direction).

In the following description, the distance in the X-axis direction shownin FIGS. 1A and 1B to FIG. 3 will be described as “width”, the distancein the Y-axis direction will be described as “length”, and the distancein the Z-axis direction will be described as “thickness, height, ordepth”. The side closer to the air bearing surface 20 in the Y-axisdirection will be described as “front side or forward” and the sideopposite to the front side will be described as “rear side or rearward”.The description will be similarly used in FIGS. 4A and 4B and subsequentdrawings.

The thin film magnetic head is, for example, a composite head capable ofexecuting the functions of both recording and reproducing. As shown inFIGS. 1A and 1B, the thin film magnetic head has a configurationobtained by stacking, on a substrate 1 made of a ceramic material suchas AlTiC (Al₂O₃.TiC), an insulating layer 2 made of a non-magneticinsulating material such as aluminum oxide (Al₂O₃, hereinbelow, simplycalled “alumina”), a reproducing head portion 100A for executing areproducing process by using a magneto-resistive (MR) effect, anisolation layer 7 made of a non-magnetic insulating material such asalumina, a recording head portion 100B of a single magnetic pole typefor executing a recording process of a perpendicular recording method,and an overcoat layer 19 made of a non-magnetic insulating material suchas alumina. The layers are stacked in this order.

The reproducing head portion 100A has, for example, a configuration inwhich a lower shield layer 3, a shield gap film 4, and an upper shieldlayer 5 are stacked in this order. In the shield gap film 4, an MRdevice 6 as a reproducing device is buried so that one end face isexposed in the recording medium facing surface (air bearing surface) 20which faces a recording medium.

The lower and upper shield layers 3 and 5 are made of, for example, amagnetic material such as a nickel iron alloy (NiFe (for example, Ni:80% by weight and Fe: 20% by weight) which will be simply called“permalloy (trademark)” hereinbelow). Each of the layers has a thicknessof about 1.0 μm to 2.0 μm. The shield gap film 4 is used to electricallyisolate the MR device 6 from the periphery and is made of, for example,a non-magnetic insulating material such as alumina. The MR device 6 isprovided to execute a reproducing process by using GMR (GiantMagneto-resistive) or TMR (Tunneling Magneto-resistive) effect.

The recording head portion 100B has a configuration obtained by, forexample, sequentially stacking a return yoke layer 8 buried by aninsulating layer 9, an auxiliary return yoke layer 10, a yoke layer 11,and a thin film coil 13 buried by insulating layers 12 and 14, a seedlayer 15 having an opening (back gap 15BG) for connection, a magneticpole layer 16 covered with a gap layer 17, and a write shield layer(magnetic shield layer) 18. FIG. 2 shows the return yoke layer 8,auxiliary return yoke layer 10, yoke layer 11, thin film coil 13, seedlayer 15, magnetic pole layer 16, and write shield layer 18 in therecording head portion 100B. FIG. 3 shows the seed layer 15, magneticpole layer 16, gap layer 17, and write shield layer 18.

The return yoke layer 8 is provided to return a magnetic flux emittedfrom the magnetic pole layer 16 and magnetized a recording medium and ismade of, for example, a magnetic material such as permalloy or an ironcobalt nickel (FeCoNi) alloy. The return yoke layer 8 extends in thedirection apart from the air bearing surface 20 and has, for example, arectangular shape (having a width W3) in plan view. The auxiliary returnyoke layer 10 is provided to lead the magnetic flux used for recordingto the return yoke layer 8, is exposed from the air bearing surface 20and connected to the return yoke layer 8. The yoke layer 11 is providedto connect the return yoke layer 8 and the magnetic pole layer 16,recessed from the air bearing surface 20 and connected to the returnyoke layer 8. Each of the auxiliary return yoke layer 10 and the yokelayer 11 is made of, for example, a magnetic material as that of thereturn yoke layer 8 and has a rectangular shape (having the width W3) inplan view. “Connection” in the specification means not only a simplecontact but also a contact and magnetic conduction. The insulating layer9 is made of, for example, a non-magnetic insulating material such asalumina.

The thin film coil 13 is provided to generate a magnetic flux forrecording. The thin film coil 13 has, for example, a winding structurethat a wire is wound in a spiral shape around the yoke layer 11 as acenter, and is made of a high-conductive material such as copper (Cu).In each of FIGS. 1A, 1B and FIG. 2, only a part of a plurality of turnsconstructing the thin film coil 13 is shown. The insulating layers 12and 14 are provided to electrically isolate the thin film coil 13 fromthe periphery and are made of, for example, a non-magnetic insulatingmaterial such as alumina.

The seed layer 15 is used for performing a plating process and has, forexample, a shape in plan view corresponding to the shape in plan view ofthe magnetic pole layer 16.

The magnetic pole layer 16 is provided to contain the magnetic fluxgenerated by the thin film coil 13 and emit the magnetic flux toward arecording medium, and extends from the air bearing surface 20 in thedirection apart from the air bearing surface 20. The magnetic pole layer16 includes, for example, a tip portion 16A (magnetic pole tip portion)extending from the air bearing surface 20 in the direction apart fromthe air bearing surface 20 and having a uniform width W1 (=about 0.15μm) specifying the recording track width, and a rear end portion 16Bconnected to the rear end of the tip portion 16A and having a width W2larger than the width W1 of the tip portion 16A (W2>W1). The rear endportion 16B has the uniform width W2 in its rear part and is graduallytapered to the tip portion 16A. The position from which the width of themagnetic pole layer 16 increases from the tip portion 16A (width W1) tothe rear end portion 16B (width W2) is called a flare point FP.

The gap layer 17 is provided to construct a gap for providing magneticisolation between the magnetic layer 16 and the write shield layer 18.The gap layer 17 includes a gap layer portion 17A (first gap layer)which is disposed so as to cover the side faces and a peripheral area ofthe magnetic layer 16 and is adjacent to the magnetic pole layer 16, anda gap layer portion 17B (second gap layer) disposed so as to cover thetop face of the magnetic pole layer 16 and is adjacent to the magneticpole layer 16. The level of the top face of the gap layer portion 17Ais, for example, higher than that of the gap layer portion 17B.

The write shield layer 18 is provided to contain a spread portion of themagnetic flux emitted from the magnetic pole layer 16 and to prevent thespread of the magnetic flux. For example, the write shield layer 18extends from the air bearing surface 20 to the flare point FP andsurrounds the tip portion 16A of the magnetic layer 16 from the threedirections. The three directions denotes a trailing direction (mediumoutflow direction) with respect to the position in which the magneticpole layer 16 is disposed as a reference and two side directionsorthogonal to the trailing direction (hereinbelow, also simply called“three directions”). The “trailing direction” is a direction of outflowof a recording medium when a moving state of the recording mediumtraveling in the medium travel direction B (refer to FIGS. 1A and 1B) isregarded as a flow. In this case, the trailing direction is an upwarddirection in the thickness direction (Z-axis direction). The directionof inflow is called a “leading direction (medium inflow direction)” andis a downward direction in the thickness direction. The “two sidedirections” denote both directions in width (rightward and leftwarddirections in the X-axis direction). The write shield layer 18 isconnected to the auxiliary return yoke layer 10 via two connection holesJ provided so as to penetrate both of the insulating layer 12 and thegap layer portion 17A. The write shield layer 18 has a rectangular shape(having the width W3) in plan view. The number of the connection holes Jand the positions of the connection holes J can be arbitrarily set.

The operation of the thin film magnetic head will now be described withreference to FIGS. 1A and 1B and FIG. 2.

In the thin film magnetic head, at the time of recording information,when a current flows into the thin film coil 13 of the recording headportion 100B via a not-shown external circuit, a magnetic flux isgenerated by the thin film coil 13. The magnetic flux generated at thistime is contained by the magnetic pole layer 16 and flows from the rearend portion 16B to the tip portion 16A in the magnetic pole layer 16.Since the magnetic flux flowing in the magnetic pole layer 16 isconverged at the flare point FP as the width of the magnetic pole layer16 decreases, the magnetic flux is concentrated in the trailing sideportion of the tip portion 16A. When the magnetic flux is emitted fromthe tip portion 16A to the outside, a recording magnetic field isgenerated in the direction orthogonal to the surface of a recordingmedium and the recording medium is magnetized in the perpendiculardirection by the recording magnetic field, thereby magneticallyrecording information onto the recording medium. The spread component ofthe magnetic flux emitted from the tip portion 16A is contained by thewrite shield layer 18, so that the spread of the magnetic flux isprevented. The magnetic flux contained by the write shield layer 18flows into the auxiliary return yoke layer 10 via the connection holes Jand further flows into the return yoke layer 8. The magnetic flux whichhas magnetized the recording medium is returned to the return yoke layer8 via the auxiliary return yoke layer 10.

At the time of reproducing, when a sense current flows into the MRdevice 6 in the reproducing head portion 10A, the resistance value ofthe MR device 6 changes according to a signal magnetic field forreproducing from the recording medium. Since the resistance change isdetected as a change in the sense current, the information recorded onthe recording medium is magnetically read.

A method of manufacturing the thin film magnetic head shown in FIGS. 1Aand 1B to FIG. 3 will now be described with reference to FIGS. 4A and 4Bto FIG. 20. FIGS. 4A and 4B to FIG. 18 are diagrams for explainingprocesses of manufacturing the thin film magnetic head. FIGS. 4A and 4Bto FIGS. 11A and 11B show sectional configurations corresponding toFIGS. 1A and 1B. FIGS. 12 to 18 are plan views showing configurationscorresponding to FIGS. 5A and 5B to FIGS. 11A and 11B, respectively.FIG. 19 is a plan view showing the configuration for explaining anexample of formation of the seed layer 15. FIG. 20 shows dependency onan incident angle of an etching rate. The lateral axis of FIG. 20denotes the incident angle θ (°) of an ion beam and the vertical axisindicates the etching rate (nm/minute). “20A” indicates an etching rateto a photoresist, and “20B” indicates an etching rate to alumina.

In the following, first, an outline of processes of manufacturing awhole thin film magnetic head will be described. After that, processesof forming main components (the magnetic pole layer 16, gap layer 17,and write shield layer 18) of the recording head portion 100B to whichthe method of manufacturing the thin film magnetic head of the inventionis applied will be described in detail. Description of the materials,dimensions, structural features, and the like of the series of thecomponents of the thin film magnetic head which have been alreadydescribed in detail will not be repeated.

A plurality of thin film magnetic heads are manufactured in a lump by,for example, sequentially forming components in parallel in a pluralityof positions on a wafer and stacking the components by mainly using athin film process including a film forming technique such as plating andsputtering, a patterning technique such as photolithography technique,and an etching technique such as dry etching. Specifically, first, theinsulating layer 2 is formed on the substrate 1 and, after that, thelower shield layer 3, the shield gap film 4 in which the MR device 6 isburied, and the upper shield layer 5 are stacked on the insulating layer2 in accordance with this order, thereby forming the reproducing headportion 100A. Subsequently, the isolation layer 7 is formed on thereproducing head portion 100A. On the isolation layer 7, by sequentiallystacking the return yoke layer 8 buried by the insulating layer 9, theauxiliary return yoke layer 10, yoke layer 11 and thin film coil 13buried by the insulating layers 12 and 14, seed layer 15, magnetic polelayer 16 covered with the gap layer 17, and write shield layer 18, therecording head portion 100B is formed. Finally, the overcoat layer 19 isformed on the recording head portion 100B and, after that, the airbearing surface 20 is formed by using mechanical process and polishingprocess, thereby completing the thin film magnetic head.

At the time of forming the main components of the recording head portion100B, the insulating layers 12 and 14 are formed so as to bury theauxiliary return yoke layer 10, yoke layer 11, and thin film coil 13,and a flat surface M1 is constructed by the insulating layers 12 and 14and the yoke layer 11. After that, first, as shown in FIGS. 4A and 4B, aprecursor seed layer 15Z made of a magnetic material such as permalloyor a metal material such as copper is formed to a thickness of about0.01 μm to 0.1 μm on the flat surface M1 by using sputtering or thelike.

Subsequently, by using, for example, ion milling, the precursor seedlayer 15Z is etched and patterned, thereby forming the seed layer 15 ina pattern as shown in FIGS. 5A and 5B and FIG. 12. The seed layer 15 isformed so that, for example, its outline becomes larger than the outlineof the magnetic pole layer 16 to be formed in a post process. Byselectively removing a region in which the yoke layer 11 and themagnetic pole layer 16 are connected in a post process in the precursorseed layer 15Z, the back gap 15BG is formed in the seed layer 15.

In particular, at the time of forming the seed layer 15, as describedabove, considering that a plurality of thin film magnetic heads areformed in parallel on the wafer, for example, as shown in FIG. 19,preferably, by patterning the precursor seed layer 15Z, a lead layer 50for energization is patterned together with the seed layer 15 on a wafer40, and the seed layer 15 is disposed for each region (thin filmmagnetic head formation region) R surrounded by the lead layer 50, andeach seed layer 15 is connected to the lead layer 50. Closing lines D inFIG. 19 express portions to be diced in the wafer 40 after completion ofthe thin film magnetic heads.

Subsequently, a photoresist is applied on the seed layer 15 andpatterned by using the photolithography technique, thereby forming aprecursor photoresist layer 31Z in a pattern as shown in FIGS. 5A and 5Band FIG. 12. At the time of forming the precursor photoresist layer 31Z,for example, a portion (corresponding portion) 31ZP having a width W10larger than the width W1 (W10>W1) of the tip portion 16A of the magneticpole layer 16 is included.

By ashing the precursor photoresist layer 31Z to narrow the width of acorresponding portion 31ZP from W10 to W1, as shown in FIGS. 6A and 6Band FIG. 13, a photoresist layer 31 (first photoresist layer) ispatterned so as to include a corresponding portion 31P having the widthW1 and have a shape in plan view corresponding to the shape in plan viewof the magnetic pole layer 16.

As shown in FIGS. 7A and 7B and FIG. 14, for example, by using CVD(Chemical Vapor Deposition) or sputtering, the gap layer portion 17Amade of alumina is formed to a thickness equal to or less than about 0.2μm, concretely, about 0.1 μm so as to cover the photoresist layer 31 andits peripheral region. Subsequently, the photoresist layer 32 (secondphotoresist layer) is formed so as to cover the gap layer portion 17A.The photoresist layer 32 is formed so that, for example, the gap layerportion 17A is buried, that is, the level of the top face of thephotoresist layer 32 is higher than that of the gap layer portion 17A.

Subsequently, by using ion milling, for example, the photoresist layer32, gap layer portion 17A, and photoresist layer 31 are etched(over-etched) part way, thereby exposing the photoresist layer 31 asshown in FIGS. 8A and 8B and FIG. 15. At the time of performing the ionmilling, for example, ion beams are emitted from directions each formingan incident angle θ in a range from about 65° to 70° with a direction Sorthogonal to the extended surface of the photoresist layer 32. Byperforming the ion million with the etching parameter, as shown in FIG.20, the etching rate (20A) to the photoresist (photoresist layers 31 and32) and the etching rate (20B) to alumina (gap layer portion 17A) becomeclose to each other and the photoresist and alumina are etched to almostthe same extent. Therefore, the photoresist layers 31 and 32 and the gaplayer portion 17A are etched so as to be almost planarized. To bestrict, as obvious from FIG. 20, also in the case where the incidentangle θ of the ion beam is set within the range, the etching rate to thephotoresist becomes slightly higher than the etching rate to alumina. Asshown in FIGS. 8A and 8B, the photoresist layers 31 and 32 areexcessively etched more than the gap layer portion 17A.

Subsequently, by removing both of the photoresist layers 31 and 32 byashing, as shown in FIGS. 9A and 9B and FIG. 16, a magnetic poleformation region T which is surrounded by the gap layer portion 17A isformed in a region from which the photoresist layer 31 has been removed,and the seed layer 15 is exposed in the magnetic pole formation regionT. The magnetic pole formation region T is a region in which themagnetic pole layer 16 is to be formed in a post process and is a spaceregion in which the plane shape of the photoresist layer 31 istransferred. At the time of forming the magnetic pole formation regionT, for example, the etching amount of the gap layer portion 17A isadjusted in a preceding process so that the depth H of the magnetic poleformation region T becomes equal to or larger than the thickness of themagnetic pole layer 16.

Subsequently, current is passed to the seed layer 15, thereby growing aplating film made of a magnetic material such as an iron cobalt basealloy (FeCo) or a cobalt iron nickel base alloy (CoFeNi) in the magneticpole formation region T, thereby forming the magnetic pole layer 16 inthe pattern as shown in FIGS. 10A and 10B and FIG. 17. By the growth ofthe plating film in the magnetic pole formation region T in which theshape in plan view of the photoresist layer 31 has been transferred, themagnetic pole layer 16 is formed so as to include, from the front side,the tip portion 16A having the width W1 and the rear end portion 16Bconnected to the tip portion 16A.

Subsequently, the plating film made of a non-magnetic metal materialsuch as rhodium (Rh) or a non-magnetic metal compound material such asnickel phosphorus (NiP) is grown on the magnetic pole layer 16 in themagnetic pole formation region T by continuously using the seed layer15, thereby forming the gap layer portion 17B to the thickness of about0.05 μm as shown in FIGS. 10A and 10B and FIG. 17. By the operations,the magnetic pole layer 16 is surrounded by the gap layer 17 consistingof the gap layer portions 17A and 17B from the three directions.

As shown in FIGS. 11A and 11B and FIG. 18, by selectively etching boththe insulating layer 12 and the gap layer portion 17A, the twoconnection through holes J are selectively formed. Finally, a framepattern (not shown) made by a photoresist is formed on the gap layer 17and, after that, a plating film made of permalloy or a cobalt ironnickel alloy is grown in the frame pattern, thereby forming the writeshield layer 18 having a thickness of about 0.2 μm to 1.0 μm as shown inFIGS. 11A and 11B and FIG. 18. At the time of forming the write shieldlayer 18, for example, as shown in FIG. 11A, the tip portion 16A of themagnetic pole layer 16 is surrounded from the three directions of thetrailing direction (upward direction in the drawing) and two sidedirections (lateral directions in the drawing). In such a manner, themain components of the recording head portion 100B are completed.

Since the characteristic manufacturing process is used in the method ofmanufacturing the thin film magnetic head according to the embodiment,the thin film magnetic head having the write shield layer 18 disposed soas to surround the tip portion 16A of the magnetic pole layer 16 fromthree directions can be formed easily with high precision for thefollowing three reasons.

First, the gap length between the magnetic pole layer 16 and the writeshield layer 18 can be controlled with high precision. FIG. 21 is adiagram for explaining the advantage of the method of manufacturing athin film magnetic head according to the embodiment. FIG. 22 is adiagram for explaining the problem of the method of manufacturing a thinfilm magnetic head as a comparative example of the embodiment. Each ofFIGS. 21 and 22 shows an enlarged sectional configuration of the maincomponents of the thin film magnetic head illustrated in FIG. 1A.

As shown in FIG. 22, the main components of the thin film magnetic headof the comparative example include: the magnetic pole layer 116 (tipportion 116A); the write shield layer 118 constructed by three portions(write shield layer portions 118A, 118B, and 118C) and disposed so as tosurround the magnetic pole layer 116 from three directions; and the gaplayer 117 constructed by three portions (gap layer portions 117A, 117B,and 117C) and disposed so as to be sandwiched by the magnetic pole layer116 and the write shield layer 118.

The main components of the thin film magnetic head are formed, forexample, by the following procedure. First, by using a plating process,the write shield layer portions 118A and 118B are formed on both sidesof the magnetic pole layer 116 with a gap D2 together with the magneticpole layer 116. After that, by using sputtering, the gap layer portions117A and 117B are formed so as to bury the gap D2, thereby constructingthe flat face M2. Subsequently, by continuously using sputtering, thegap layer portion 117C is formed so as to cover the trailing side of themagnetic pole layer 116. After that, by using a plating process, thewrite shield layer portion 118C is formed on the gap layer portion 117Cso as to be connected to the write shield layer portions 118A and 118B.In such a manner, the main components of the thin film magnetic head arecompleted.

By using the manufacturing process, the write shield layer 118 can beformed so as to surround the magnetic pole layer 116 from threedirections. In this case, the gap D2 is specified on the basis ofpattern precision of the photolithography technique employed at the timeof forming the write shield layer portions 118A and 118B, so that theformation precision of the gap D2 is not sufficiently high. The gap D2is one of factors exerting an influence on the recordingcharacteristics. Concretely, when the gap D2 is too narrow, the magneticflux emitted from the magnetic pole layer 116 does not easily spread toboth sides but the recording magnetic field intensity deteriorates. Onthe other hand, when the gap D2 is too wide, the recording magneticfield intensity is high but the magnetic flux tends to spread to bothsides. Consequently, the gap D2 has to be controlled with high precisionto a desired value. In the comparative example, precision of formationof the gap D2 is insufficient, so that the gap D2 cannot be controlledwith high precision.

In the embodiment, as shown in FIG. 21, the gap D1 between the magneticpole layer 16 and the write shield layer 18 is specified on the basis ofthe thickness of the gap layer portion 17A. In this case, different fromthe comparative example in which the gap D2 is specified on the basis ofthe pattern precision of the photolithography technique, the gap D1 iscontrolled on the basis of film formation time of sputtering at the timeof forming the gap layer portion 17A, so that the formation precision ofthe gap D1 becomes sufficient. Therefore, the gap D1 can be controlledwith high precision. Concretely, for example, the gap D1 can becontrolled with high precision so as to achieve a very narrow width ofabout 0.1 μm or less.

Second, the thickness of the magnetic pole layer 16 can be controlledwith high precision. To be specific, in the case of the comparativeexample (refer to FIG. 22), to form the flat face M2, the whole has tobe polished by using a polishing technique such as CMP (ChemicalMechanical Polishing). In this case, however, the thickness C2 of themagnetic pole layer 116 is specified on the basis of the polishingprecision, so that the formation precision of the thickness C2 of themagnetic pole layer 116 is insufficient. In contrast, in the embodiment(refer to FIG. 21), the thickness C1 of the magnetic pole layer 16 isspecified on the basis of the thickness of the film formed at the timeof the plating process. In this case, different from the comparativeexample in which the thickness C2 of the magnetic pole layer 116 isspecified on the basis of the polishing precision, the thickness C1 ofthe magnetic pole layer 16 is controlled on the basis of the processtime (film formation time) of the plating process, so that the formationprecision of the thickness C1 is assured. Thus, the thickness C1 of themagnetic pole layer 16 can be controlled with high precision.

Third, the write shield layer 18 having the characteristic configurationof surrounding the tip portion 16A of the magnetic pole layer 16 fromthree directions can be easily formed. In the comparative example (referto FIG. 21), the write shield layer 118 is constructed by three portions(write shield layer portions 118A, 118B, and 118C), to form the writeshield layer 118, as described above, at least two processes of aprocess of forming the write shield layer portions 118A and 118B and aprocess of forming the write shield layer portion 118C are necessary. Inthis case, the process of forming the write shield layer 118 becomescomplicated and long time is required. In contrast, in the embodiment(refer to FIG. 21), the write shield layer 18 is formed as a singlebody, so that a single process is necessary to form the write shieldlayer 18 and the process of forming the write shield layer 18 isfacilitated. Obviously, in the embodiment, different from thecomparative example, the polishing process is not required, so that theforming process is facilitated also from this viewpoint. Therefore, thewrite shield layer 18 can be easily formed.

In addition, in the embodiment, the seed layer 15 is formed so as to bein a predetermined pattern shape by patterning the precursor seed layer15Z, and the seed layer 15 is selectively disposed only in necessaryportions. After that, the magnetic pole layer 16 and the gap layerportion 17B are formed by using the seed layer 15. Consequently,different from the case where the seed layer 15 is formed on the wholesurface without being patterned, it is unnecessary to remove unnecessaryportions of the seed layer 15 after forming the magnetic pole layer 16and the like. Therefore, in this viewpoint as well, the invention cancontribute to facilitate the manufacturing of the thin film magnetichead.

In particular, in the embodiment, the gap layer portions 17A and 17Bconstructing the gap layer 17 are formed in different processes.Different from the case of integrally forming the gap layer portions 17Aand 17B in a single process, the thickness of each of the gap layerportions 17A and 17B can be controlled independently. For example, thegap layer 17 can be formed so that the gap layer portion 17A is thickerthan the gap layer portion 17B.

In the embodiment, as shown in FIG. 19, the plurality of seed layers 15are connected to the lead layer 50 on the wafer 40, so that current canbe simultaneously passed to the plurality of seed layers 15 by using thelead layer 50. After completion of the thin film magnetic head, thewafer 40 is diced and the lead layer 50 is removed, thereby enabling theseed layers 15 to be electrically isolated from each other.

In the embodiment, the outline of the seed layer 15 is set to be largerthan that of the magnetic pole layer 16. Consequently, even if theformation position of the seed layer 15 is deviated a little, themagnetic pole layer 16 can be stably formed by using the seed layer 15.

In the embodiment, at the time of forming the magnetic pole layer 16 andthe gap layer portion 17B by using the plating process, in any of thecases, the seed layer 15 is used. It is therefore unnecessary to form aseed layer each time the magnetic pole layer 16 or the gap layer portion17B is formed. Thus, the invention can contribute to facilitate themanufacturing of the thin film magnetic head also from this viewpoint.

In the embodiment, at the time of forming the photoresist layer 31, theprecursor photoresist layer 31Z including the corresponding portion 31ZP(having width W10) is formed and, after that, the corresponding portion31ZP is narrowed from W10 to W1 by ashing the precursor photoresistlayer 31Z. Consequently, by using the ashing process on the photoresist,the corresponding portion 31P can be formed with high precision so as tohave the very narrow width W1 which cannot be realized with the patternprecision of the photolithography technique. Accordingly, the tipportion 16A of the magnetic pole layer 16 can be also formed with highprecision. Concretely, the width of the corresponding portion 31P whichcan be formed with sufficiently high precision at the time of using thephotolithography technique is about 0.2 μm. In contrast, in theembodiment using the ashing process, the corresponding portion 31P canbe formed with high precision so that its width becomes less than about0.2 μm. To form the corresponding portion 31P having the very narrowwidth W1, for example, a method of forming the corresponding portion31ZP having the width W10 and, after that, narrowing the width of thecorresponding portion 31ZP by using an etching technique such as ionmilling can be also employed. However, the precision of the narrowingprocess by the ashing process to a width less than about 0.2 μm ishigher than that of the etching technique. Therefore, it is preferableto use the ashing process at the time of forming the correspondingportion 31P with high precision.

In the embodiment, as shown in FIGS. 7A and 7B and FIGS. 8A and 8B, atthe time of etching the photoresist layers 31 and 32 and the gap layerportion 17A by using ion milling, the incident angle θ of an ion beam isset within the range from 65° to 70°, so that the etching rate of thephotoresist layers 31 and 32 and that of the gap layer portion 17Abecome close to each other and the photoresist layers 31 and 32 and thegap layer portion 17A are etched so as to be almost planarized.Therefore, it can prevent a situation such that the photoresist layers31 and 32 softer than the gap layer portion 17A are excessively etchedand dissipated and, after that, parts in the seed layer 15 and the gaplayer portion 17A, which are not intended to be etched, areunintentionally etched. In particular, by using the etching technique,as compared with the case of using the polishing technique such as CMPrequiring longer time for a process, etching process can be performed inshorter time.

In the embodiment, as shown in FIGS. 9A and 9B and FIG. 21, when themagnetic pole formation region T for forming the magnetic pole layer 16is formed, the depth H of the magnetic pole formation region T is set tobe larger than the thickness C1 of the magnetic pole layer 16, so thatthe depth H has a margin with respect to the thickness C1. Therefore, aninconvenience which may occur in the case where the depth H is madecoincide with the thickness C1, that is, an inconvenience that themagnetic pole layer 16 is formed thickly due to a formation precisionerror of the thickness C1 or the like and, as a result, the magneticpole layer 16 and the write shield layer 18 are unintentionallyconnected to each other can be avoided.

The thin film magnetic head according to the embodiment has the gaplayer portions 17A adjacent to the magnetic pole layer 16 in the twoside directions, the gap layer portion 17B adjacent to the magnetic polelayer 16 in the trailing direction, and the write shield layer 18surrounding the tip portion 16A of the magnetic pole layer 16 from threedirections of the trailing direction and the two side directions via thegap layer portions 17A and 17B. Consequently, the thin film magnetichead can be manufactured by using the method of manufacturing the thinfilm magnetic head according to the embodiment.

Although, in the embodiment, as shown in FIG. 21, the outline of theseed layer 15 is set to be larger than that of the magnetic pole layer16, the invention is not limited to the arrangement. For example, asshown in FIG. 23, the outline of the seed layer 15 may be equal to thatof the magnetic pole layer 16. In this case as well, effects similar tothose of the foregoing embodiment can be obtained. As described above,when the inconvenience that the magnetic pole layer 16 cannot be stablyformed due to a deviation of the formation position of the seed layer 15is considered, it is preferable to set the outline of the seed layer 15to be larger than that of the magnetic pole layer 16 as shown in FIG.21.

In the embodiment, as shown in FIG. 21, the depth H of the magnetic poleformation region T is set to be larger than the thickness C1 of themagnetic pole layer 16. However, the invention is not always limited tothis arrangement. For example, as shown in FIG. 24, the depth H may beequal to the thickness C1. In this case as well, effects similar tothose of the foregoing embodiment can be obtained. As described above,when the inconvenience that the magnetic pole layer 16 and the writeshield layer 18 are unintentionally coupled to each other due to aprecision error of the thickness C1 is considered, it is preferable toset the depth H to be larger than the thickness C1.

In the embodiment, as shown in FIGS. 7A and 7B and FIGS. 8A and 8B, tomake the photoresist layer 31 expose to the outside, the photoresistlayer 32, gap layer portion 17A, and photoresist layer 31 areover-etched. However, the invention is not always limited to thearrangement. For example, only the photoresist layer 32 and the gaplayer portion 17A may be over-etched. In this case as well, effectssimilar to those of the foregoing embodiment can be obtained. However,when considering the inconvenience such that the photoresist layer 31 isnot exposed due to a precision error of the etching amount in the casewhere only the photoresist layer 32 and the gap layer portion 17A areover-etched, it is preferable to over-etch the photoresist layer 31together with the photoresist layer 32 and the gap layer portion 17A.

In the embodiment, as shown in FIGS. 11A and 11B, the write shield layer18 is formed by the single process. The invention, however, is notalways limited to the method but, for example, the write shield layer 18may be formed by a plurality of processes. FIGS. 25A and 25B to FIGS.30A and 30B are diagrams for explaining three modifications of themethod of forming the write shield layer 18. FIGS. 25A and 25B to FIGS.27A and 27B show a first modification. FIGS. 28A and 28B to FIGS. 29Aand 29B show a second modification. FIGS. 30A and 30B show a thirdmodification.

In the first modification, as shown in FIGS. 11A and 10B, the gap layer17B is formed. After that, as shown in FIGS. 25A and 25B, thephotoresist film is patterned by using the photolithography technique,thereby forming a frame pattern 33 so as to cover the region other thanthe formation region of the write shield layer 18. Subsequently, byselectively growing a plating film on the gap layer 17B in the magneticpole formation region T by using the frame pattern 33 and the seed layer15, a write shield layer portion 18A (first magnetic shield layerportion) as a part of the write shield layer 18 is patterned.Subsequently, as shown in FIGS. 26A and 26B, for example, by usingsputtering, a write shield layer portion 18B (second magnetic shieldlayer portion) as another part of the write shield layer 18 is formed soas to cover the gap layer portion 17A, write shield layer portion 18A,and frame pattern 33. At the time of forming the write shield layerportion 18A, the front portion of the write shield layer portion 18A isset to surround the tip portion 16A of the magnetic pole layer 16 fromthree directions of the trailing direction and two side directions.Finally, the frame pattern 33 is lifted off together with the excessivewrite shield layer portion 18B while partially leaving the write shieldlayer portion 18B, thereby forming the write shield layer 18 as anassembly of the write shield layer portions 18A and 18B as shown inFIGS. 27A and 27B.

In the second modification, the frame pattern 33 is formed together withthe write shield layer portion 18A by using a method similar to that ofthe first modification. After that, first, as shown in FIGS. 28A and28B, a seed layer 25 for performing a plating process is formed byusing, for example, sputtering so as to cover the gap layer portion 17A,write shield layer portion 18A, and frame pattern 33. At the time offorming the seed layer 25, for example, by partly connecting the seedlayer 25 to the seed layer 15, current can be passed to the seed layer25 via the seed layer 15. Subsequently, by selectively growing a platingfilm by using the seed layer 25 together with the frame pattern 33, thewrite shield layer portion 18B is formed in a pattern. Finally, bylifting off the frame pattern 33 together with the excessive seed layer25, as shown in FIGS. 29A and 29B, the write shield layer 18 includingthe write shield layer portions 18A and 18B is formed.

As the third modification, the write shield layer portion 18A is formedby using a method similar to that of the first modification and theframe pattern 33 used to form the write shield layer portion 18A isremoved. After that, first, as shown in FIGS. 30A and 30B, a seed layer35 for performing a plating process is formed in a pattern in a regionin which the write shield layer portion 18B is to be formed in a postprocess on the gap layer portion 17A and the write shield layer portion18A. At the time of forming the seed layer 35, for example, in a mannersimilar to the case of forming the seed layer 15 in the foregoingembodiment, a precursor seed layer (not shown) for forming the seedlayer 35 is formed on the whole face and is patterned by using thephotolithography technique and the etching technique. At this time, forexample, by partly connecting the seed layer 35 to the seed layer 15,current can be passed to the seed layer 35 via the seed layer 15.Subsequently, by patterning the photoresist film by using thephotolithography technique, a frame pattern 34 is formed so as to coverthe region other than the formation region of the write shield layerportion 18B. After that, by selectively growing a plating film by usingthe seed layer 35 together with the frame pattern 34, the write shieldlayer portion 18B is formed. After that, by removing the frame pattern34, the write shield layer 18 including the write shield layer portions18A and 18B is formed.

Also in the case of forming the write shield layer 18 by using any ofthe first to third modifications, effects similar to those of theforegoing embodiment can be obtained.

Although the gap layer portions 17A and 17B are adjacent to the wholemagnetic pole layer 16 as shown in FIGS. 1A and 1B in the embodiment,the invention is not always limited to the configuration. For example,as shown in FIGS. 31A and 31B, the gap layer portions 17A and 17B may beadjacent only to the tip portion 16A of the magnetic pole layer 16. Themethod of manufacturing a thin film magnetic head having theconfiguration is substantially the same as that described in theforegoing embodiment except for the point that the gap layer portion 17Ais formed so as to be adjacent only to the tip portion 16A in two sidedirections and the gap layer portion 17B is formed so as to be adjacentonly to the tip portion 16A in the trailing direction. In this case, asthe region surrounded by the gap layer portion 17A, in place of themagnetic pole formation region T for forming the magnetic pole layer 16described in the foregoing embodiment, a magnetic pole tip formationregion TN for forming the tip portion 16A is formed. In this case aswell, effects similar to those of the foregoing embodiment can beobtained. In the case of manufacturing the thin film magnetic headhaving the configuration shown in FIGS. 31A and 31B, as the method offorming the write shield layer 18, the single process method describedin the foregoing embodiment or the plural-process method described inthe first to third modifications (FIGS. 25A and 25B to FIGS. 30A and30B) may be used.

Although the invention has been described by the embodiment andmodifications, the invention is not limited to the embodiments but maybe variously modified. Concretely, for example, the case of applying theinvention to a single magnetic pole type head has been described in theforegoing embodiment. The invention, however, is not always limited tothe case but can be applied to a ring-type head. Although the case ofapplying the invention to a composite thin film magnetic head has beendescribed in the foregoing embodiment, the invention is not alwayslimited to the case but can be applied to, for example, a recording-onlythin film magnetic head having an inductive magnetic transducer forwriting and a thin film magnetic head having an inductive magnetictransducer for both recording and reproducing. Obviously, the inventioncan be also applied to a thin film magnetic head in which a device forwriting and a device for reading are stacked in the order opposite tothe above-described order.

Although the case of applying the invention to a thin film magnetic headof the perpendicular recording method has been described in theforegoing embodiment, the invention is not always limited to the headbut can be also applied to a thin film magnetic head of the longitudinalrecording method.

As described above, in the method of manufacturing a thin film magnetichead according to the first aspect of the invention, in a magnetic poleformation region surrounded by a first gap layer, a magnetic pole layerand a second gap layer are formed, and the magnetic pole layer iscovered with the first and second gap layers from three directions.After that, a magnetic shield layer is formed on the first and secondgap layer so as to surround the magnetic pole tip portion of themagnetic pole layer from three directions. Consequently, based on thecharacteristic manufacturing process, the thin film magnetic head inwhich the magnetic shield layer is disposed so as to surround themagnetic pole layer from three directions of the medium outflowdirection and two side directions can be easily formed with highprecision.

In the method of manufacturing a thin film magnetic head according tothe second aspect of the invention, in a magnetic pole tip formationregion surrounded by a first gap layer, a magnetic pole tip portion anda second gap layer are formed, and the magnetic pole tip portion issurrounded from three directions by the first and second gap layers.After that, a magnetic shield layer is formed on the first and secondgap layer portions so as to surround the magnetic pole tip portion fromthree directions of the medium outflow direction and two sidedirections. Thus, the thin film magnetic head in which the magneticshield layer is disposed so as to surround the magnetic pole tip portionfrom three directions of the medium outflow direction and two sidedirections can be easily formed with high precision.

The thin film magnetic head according to the first aspect of theinvention has: the first gap layer adjacent to the magnetic pole layerin two side directions; the second gap layer disposed adjacent to themagnetic pole layer in the medium outflow direction; and the magneticshield layer surrounding the magnetic pole tip portion of the magneticpole layer from three directions of the medium outflow direction and thetwo side directions via the first and second gap layers. Thus, the thinfilm magnetic head can be manufactured by using the method ofmanufacturing a thin film magnetic head according to the first aspect ofthe invention.

The thin film magnetic head according to the second aspect of theinvention has: the first gap layer adjacent to the magnetic pole tipportion in two side directions; the second gap layer adjacent to themagnetic pole tip portion in the medium outflow direction; and themagnetic shield layer surrounding the magnetic pole tip portion fromthree directions of the medium outflow direction and the two sidedirections via the first and second gap layers. Thus, the thin filmmagnetic head can be manufactured by using the method of manufacturing athin film magnetic head according to the second aspect of the invention.

In addition to the above, in the method of manufacturing a thin filmmagnetic head of the invention, by forming the magnetic pole layer andthe second gap layer by using a seed layer, the invention can contributeto facilitate manufacturing of the thin film magnetic head also fromthis viewpoint.

In the method of manufacturing a thin film magnetic head of theinvention, when the outline of the seed layer is larger than that of themagnetic pole layer, the magnetic pole layer can be stably formed byusing the seed layer.

In the method of manufacturing a thin film magnetic head according tothe invention, a precursor photoresist layer is formed so as to includea portion having a width larger than the width of the magnetic pole tipportion and, after that, a second photoresist layer is formed bynarrowing the width of the portion by ashing the precursor photoresistlayer. Consequently, the second photoresist layer can be formed withhigh precision so as to have a very narrow width which cannot berealized by pattern precision of the photolithography technique and,accordingly, the magnetic pole tip portion of the magnetic pole layercan be also formed with high precision.

In the method of manufacturing a thin film magnetic head according tothe invention, by emitting an ion beam from a direction forming an anglein a range from 65° to 70° with a direction orthogonal to a planeextended from the second photoresist layer at the time of using ionmilling, the portion other than the portion to be etched in the firstgap layer can be prevented from being unintentionally etched.

In the method of manufacturing a thin film magnetic head according tothe invention, by setting the depth of the magnetic pole formationregion to be larger than the thickness of the magnetic pole layer, aninconvenience that the magnetic pole layer and the magnetic shield layerare unintentionally connected to each other can be avoided.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

1-11. (canceled)
 12. A thin film magnetic head comprising: a thin filmcoil for generating a magnetic flux; a magnetic pole layer having amagnetic pole tip portion for emitting the magnetic flux generated bythe thin film coil toward a recording medium traveling in apredetermined medium travel direction, and extending from a recordingmedium facing surface which faces the recording medium in the directionaway from the recording medium facing surface; a first gap layerdisposed so as to be adjacent to the magnetic pole layer in two sidedirections orthogonal to the medium outflow direction in the mediumtravel direction; a second gap layer disposed so as to be adjacent tothe magnetic pole layer in the medium outflow direction; and a magneticshield layer disposed so as to extend from the recording medium facingsurface in the direction away from the recording medium facing surfaceand so as to surround the magnetic pole tip portion of the magnetic polelayer from three directions of the medium outflow direction and the twoside directions via the first and second gap layers.
 13. A thin filmmagnetic head comprising: a thin film coil for generating a magneticflux; a magnetic pole layer having a magnetic pole tip portion foremitting the magnetic flux generated by the thin film coil toward arecording medium traveling in a predetermined medium travel direction,and extending from a recording medium facing surface which faces therecording medium in a direction away from the recording medium facingsurface; a first gap layer disposed so as to be adjacent to the magneticpole tip portion in two side directions orthogonal to the medium outflowdirection in the medium travel direction; a second gap layer disposed soas to be adjacent to the magnetic pole tip portion in the medium outflowdirection; and a magnetic shield layer disposed so as to extend from therecording medium facing surface in the direction away from the recordingmedium facing surface and so as to surround the magnetic pole tipportion from three directions of the medium outflow direction and thetwo side directions via the first and second gap layers.
 14. The thinfilm magnetic head of claim 12, further comprising forming a seed layerfor performing a plating process in a pattern, and the magnetic polelayer and the second gap layer are formed by growing a plating film byusing the seed layer.
 15. The thin film magnetic head of claim 13,further comprising forming a seed layer for performing a plating processin a pattern, and the magnetic pole layer and the second gap layer areformed by growing a plating film by using the seed layer.
 16. The thinfilm magnetic head of claim 14, wherein an outline of the seed layer isset to be larger than that of the magnetic pole layer.
 17. The thin filmmagnetic head of claim 15, wherein an outline of the seed layer is setto be larger than that of the magnetic pole layer.
 18. The thin filmmagnetic head of claim 12, wherein the thickness of the first gap layeris set to 0.1 μm or less.
 19. The thin film magnetic head of claim 13,wherein the thickness of the first gap layer is set to 0.1 μm or less.20. The thin film magnetic head of claim 12, wherein the magnetic polelayer is allowed to emit a magnetic flux for magnetizing the recordingmedium in the direction orthogonal to the surface of the recordingmedium.
 21. The thin film magnetic head of claim 13, wherein themagnetic pole layer is allowed to emit a magnetic flux for magnetizingthe recording medium in the direction orthogonal to the surface of therecording medium.
 22. The thin film magnetic head of claim 14, furthercomprising forming a precursor seed layer and etching and patterning theprecursor seed layer, thereby forming the seed layer.
 23. The thin filmmagnetic head of claim 15, further comprising forming a precursor seedlayer; and etching and patterning the precursor seed layer, therebyforming the seed layer.
 24. The thin film magnetic head of claim 12,forming a precursor photoresist layer so as to include a portion havinga width larger than the width of the magnetic pole tip portion; andforming the first photoresist layer by narrowing the width of theportion having the width larger than the width of the magnetic pole tipportion by ashing the precursor photoresist layer.
 25. The thin filmmagnetic head of claim 13, forming a precursor photoresist layer so asto include a portion having a width larger than the width of themagnetic pole tip portion; and forming the first photoresist layer bynarrowing the width of the portion having the width larger than thewidth of the magnetic pole tip portion by ashing the precursorphotoresist layer.